XmDropSiteUpdate modifies drop site resources associated with
the specified widget. This routine updates the drop site resources
specified in the arglist.
widget
Specifies the ID of the widget registered as a drop site
arglist
Specifies the argument list
argcount
Specifies the number of attribute/value pairs in the argument
list (arglist)
For a complete definition of DropSite and its associated resources,
see XmDropSite(3).